Improved pileup reweighting
Rework class PileUpWeight
implementing the following changes:
- The expected number of pileup interactions is now read from the event under the hood as opposed to being provided as a parameter.
- Pileup profiles needed to compute the weights are read from ROOT files with configurable paths.
- Systematic variation in pileup has been implemented.
The input ROOT files with pileup profiles are placed in the directory with catalogues. They are documented in
/pnfs/iihe/cms/store/group/HZZ2l2nu/Bonzais/Catalogs/September2018_newIDIso_v2/pileup.md